1. Technical Field
The present disclosure relates to a blank heating device, and more particularly, to a blank heating device that increases the marketability of a material and minimizes a preheating time and heat loss by enabling a divisional heating based on a size of a blank, which is a material for hot stamping, to improve heating density of the blank.
2. Description of Related Art
Generally, parts having various material strengths are used for a vehicle. For example, portions that absorb energy during a collision or overturn of the vehicle typically use materials that have a relatively weak strength. Conversely, a portion of a vehicle that maintains a shape to secure a survival space of a passenger during a collision typically requires an increased material strength. In particular, when the portions that should absorb energy during a collision have excessively high strength, impact energy is not sufficiently absorbed. Instead, the energy is intactly transferred to other portions of the vehicle, thereby transferring an excessive impact to the passenger and other parts of the vehicle.
Further, the vehicle manufactures are continuously attempting to reduce the weight and the cost of the vehicle. As a result, one component has heterogeneous strengths which are partially different from each other. Conventionally, a separate reinforcement member was attached to a portion that requires high strength after forming a component using a lower strength material. However, when a particular component is required to have different strengths per section, a material having high hardenability is typically used for an upper portion of the component and a material having low strength and low hardenability is used for a lower portion thereof. In other words, the two materials are welded together by laser to form a blank, and a final product is then manufactured through a hot stamping process. However, conventionally, there was a problem because the blank is heated using an indirection heating methods such as conduction and convection. A lengthy preheating time is required, and consequently, the heat loss is increased, a consumption amount of energy is increased, and work convenience is also degraded.
The above information disclosed in this section is intended merely to aid in the understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.